Update SRID.csv to match PostGIS 3.0.1.

Also update the code that builds it to skip the 14 values with blank strings.
Note that 3785 and 3857 were modified in 7767016.  These modifications were done here as well:
- 3785's EXTENSION was removed
- 3857's EXTENSION was removed, and a "semi_minor" parameter was added.

Author: airbreather